Roller rframe



NOV. 22, 1966 FA|RBANK$ ET AL 3,287,013

ROLLER FRAME Filed Nov. 12, 1964 2 Sheets-Sheet 1 INVENTORS HENRY N. FAIRBANKS DANIEL H. ROBBINS ATTORNEY :1... Afllthlllillll I 1965 H. N. FAIRBANKS ET AL 3,287,013

ROLLER FRAME Filed Nov. 12, 1964 2 Sheets-Sheet 2 I NVEN TOR; S.

HENRY N. FAIRBANKS DANIEL H. ROBBINS AT TORNE Y United States Patent 3,287,013 ROLLER FRAME Henry N. Fairbanks and Daniel H. Robbins, Rochester, N.Y., assignors to Itelr Corporation, Lexington, Mass., a corporation of Delaware Filed Nov. 12, 1964, Ser. No. 410,605 9 Claims. (Cl. 271-45) This invention relates to an improved transport means for feeding sheets of material through processing solutions, and more particularly to a transport means for feeding offset master sheets through a processing solution.

Prior art sensitized sheet material processors such as the one shown in US. Patent 2,889,762 assigned to the common assignee of this invention, have been found to be unsatisfactory for processing projection offset plate material such as the material marketed by the assignee under the trademark Project-A-Lith.

This material is characterized by a paper sheet that is plastic coated on both surfaces. On top of one of the plastic coatings is a sensitized emulsion. The overall thickness of this sheet is in the order of .007", and the sheet is inherently stiff in contrast to typical sensitized paper. This stiffness increases the difficulty of transporting the sheets through the processor. The problems of transportation are further increased by the emulsion surface becoming extremely soft as it is exposed to the developing agents. The soft emulsion ordinarily has a tendency to mar or become embossed during transportation through the automatic processor, and any physical damage to the emulsion affects the quality of the final printed copy. Also, as the emulsion is softened by its exposure to the developing agents, these sheets have an inherent tendency to curl, and such curl must be carefully controlled and compensated for so that the sheets can be fed accurately through the proper path of the processor without jamming or binding.

In addition to the prior art proposel of US. Patent 2,889,762 for transporting sheets through processors by means of engagement of each sheet between opposed pairs of endless belts, it has been proposed, for example in US. Patent 3,078,024, to advance a sheet of material through a processor by successive engagement between opposed rollers. These previous suggestions, when applied to the transport of offset master sheets, suffer a variety of disadvantages including damage to, or uneven processing of the emulsion surface of such sheets, and inaccurate or uneven advancing of such sheets through processors because of the curl they assume when their emulsion surfaces are softened. Furthermore, previous sheet transport means have been complex and costly to manufacture and difficult to repair and service in part because disassembly and assembly have required time and skill.

An object of this invention is to make a simple, economic transport means that can feed offset master sheets through processing solutions accurately without sticking, binding, jamming, or other mishap, and that can subject such sheets to uniform processing without damage to or faulty processing of the emulsion surface.

Another object of the invention is to make an offset master sheet transporting means that is easy to assemble and disassemble for low manufacturing costs and economy in servicing including cleaning, repair, and replacement of parts.

Another object of the invention is to make an offset master sheet transporter of several sub-assemblies secured together in a simple manner so that such transporter can be quickly disassembled to a few basic units or subassemblies any one of which can be replaced in whole 3,287,013 Patented Nov. 22, 1966 or in part, and any one of which can be separately repaired.

Another object of the invention to make a simple turning means for directing an offset master sheet from downward travel into a processing solution to upward travel out of such processing solution.

Another object of the invention is to improve the efficiency and reduce the manufacturing and operating costs of transport means for feeding offset master sheets through processing solutions.

To these and other ends the invention resides in certain improvements and combinations, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of this specification.

In the drawings:

FIG. 1 shows an isometric view of a transport means according to the invention;

FIG. 2 shows a partial cross section of the transport means of FIG. 1; and

FIG. 3 shows an exploded view of the transport means of FIG. 1 partially showing disassembly of such transport means.

The drawings wherein corresponding parts are given the same reference numerals, illustrate an offset master sheet transporting means 10 according to the invention.

Generally, an offset master sheet is fed into transporter 10 at the top of one side and travels downward, around the bottom, back up the other side, and out the top. During a portion of such'travel, an offset master sheet is submerged in processing solution in which the transporter 10 is immersed. Such processing solution flows through all the spaces in the transporter and contacts the emulsion surface of the offset master sheet which is preferably oriented emulsion side outward.

Through spur gear 11, transporter 10 is driven by the processing unit in which it is installed, and such driving power is transmitted to the moving parts of the transporter 10, preferably by a gear train. The uppermost and lowermost of the spur gears 12 are secured respectively to upper pulley shaft 13 and lower pulley shaft 14, and the intermediate gears 12 of the gear train are arranged as connective idlers or the means for driving roller gears as will be explained below. Gears 12 can be conveniently molded of plastic and are retained on their respective shafts by retaining rings 15.

Pulley shafts 13 and 14 are provided with a plurality of preferably molded plastic pulleys 16 and 17 respectively. Alternatively, continuous rollers could be substituted for pulleys 16 and 17. A plurality of continuous endless belts 18 are entrained over pulleys 16 and 17 so that the belts 18 can be uniformly driven. Belts 18 are arranged for engaging preferably the back of an offset master sheet for feeding it through transporter 10. The natural curl of an offset master sheet after it is wetted by processing solution is such that the sheet tends to curl toward or around its back side so that it is preferred that belts 18 support the back of the sheet against such tendency to curl. With such an arrangement, the belts 18 not only provide feeding power and uniform transporting motion for such offset master sheets, but carry such sheets flat against their tendency to curl.

Offset master sheets are guided for traveling with belts 18 by means of a plurality of rollers 20 spaced along belts 18. Rollers 20 are driven uniformly and at the same rate as belts 18 by means of roller gears 19 that engage gears 12 in a driving relation. Roller gears 19 are also conveniently made of plastic and are keyed torollers 20 by means of convenient pins 21 and are secured on their shafts by retaining rings 29.

Rollers 20 are mounted in a pair of sub-assemblies supported by respective frames 22 and 23. Frames 22 and 23, with their respective roller assemblies, are arranged on opposite sides of the drive belt assembly and are secured together in an engaging and supporting relationship with the belt frame assembly for being supported by the latter. Simplicity is preferred in securing together the roller and belt assemblies, and is in part achieved by angle irons 24 by means of which frames 22 and 23 are bolted together. In assembled orientation, a plurality of rollers 20 are arranged on each side of the belt assembly for engagement with each reach of the belts 18 to form a succession of nips between rollers 20 and belts 18 on each side of transporter 10.

Rollers 20 are held in place in frames 22 and 23 by sliding engagement of notched washers or sleeves 25 with a plurality of slots 26 formed in frames 22 and 23. The sliding engagement of sleeves 25 with slots 26 allows rollers 20 to move short distances toward and away from belts 18.

Roller 20 are biased inward toward engagement with belts 18. The preferred method for biasing rollers 20 is by means of springs 27 having double arms each one of which engages a retainer notch in one of the sleeves 25 that is mounted on each roller 20. Springs 27 are preferably supported by being loosely slipped over spring mounting studs 28 formed on frames 22 and 23. Such mounting of springs 27 allows them to be removed by manual deformation without use of tools. This allows rollers 20 to be removed from their respective frames 22 and 23 merely by deforming springs 27 and slipping rollers 20 from their respective retaining slots 26. Reassembly of rollers 20 is accomplished by sliding the proper notches on sleeves 25 into engagement with slots 26 and manually bringing the arms of springs 27 into' engagement with the retainer notches provided therefore in sleeves 25.

Spring biasing of rollers 20 allows rollers 20 to be forced outward away from belts 18 in event of any mishap in driving sheets through transporter and thus helps prevent damage to transporter 10 that might be caused by a malfunction. Furthermore, the above described roller assembly is especially convenient to diassemble and assemble for repairs and service.

The course of an offset master sheet through transporter 10 is best shown in the cross section view of FIG. 2. An offset master sheet 31 is fed from an exposure or other station through input chute 30 which directs it into the nip between upper roller and belts 18. Offset master sheet 31 is preferably oriented so that its emulsion side engages roller 20 and its back side engages belts 18. In such orientation it proceeds downward on the left side of transporter 10 as illustrated through a succession of nips formed by rollers 20 and belts 18. There is only one line of engagement between each of the rollers 20 and the emulsion surface of offset master 31, so that between rollers such emulsion surface is thoroughly contacted by the processing solution in which transporter 10 is immersed.

As the leading edge of offset master 31 passes beyond the lower roller 20 in its downward travel along the left side of transporter 10 as illustrated in FIG. 2, the natural curvature of offset master 31 makes such leading edge tend to bend around belts 18 as entrained over lower pulleys 17. To assist in turning offset master 31 from its downward travel to its upward travel, a turning mech anism is arranged below low-er pulleys 17. Such turning mechanism is preferably formed to provide a plurality of raised bearing ribs or ridges spaced at intervals transversely of offset master sheet 31 to reduce the sheet surface area in contact with the turning means and hence reduce the drag on offset master sheet 31. As illustrated, such a turning mechanism can comprise a backing plate 32 to which are secured guide wires 33 that are bent to conform approximately to the curvature of lower pulleys 17. Raised ribs can also be formed by means other than guide wires, for example, by corrugations or swaged integral ridges. Backing plate 32 with its guide wires 33 4 is conveniently bolted or otherwise secured to frame 23 in such a position as to guide the leading edge of offset master sheet 31 around lower pulleys 17 and belts 18 entrained thereon and through the nip formed by lower roller 20 on the right side of the transporter 10 as illustrated in FIG. 2. Offset master 31 is then driven upward along the right side of transporter 10 as illustrated in FIG. 2 through a plurality of nips between rollers 20 and belts 18 until the trailing edge of offset master 31 passes between the upper roller 20 and belts 18.

A guide means 34 is positioned above the output side of transporter 10 for guiding offset master 31 into the next transporter for subsequent trips through other processing solutions or out of the processor as the case may be. Guide means 34 also is preferably formed of a plurality of transversely spaced ribs such as provided by backing plate 35 having guide wires 36 secured thereto for guiding the leading edge of offset master sheet 31 through the desired path.

Transporters according to the invention can be arranged in tandem for transporting offset master sheets through a plurality of processing solutions or can be arranged in other convenient ways in a variety of processors. Turning or guide means such as guide means 34 can be used to direct an offset master sheet from one transporter to the next. Various well known squeegees and fluid directing means can easily be used in association with transporters according to the invention, and known input and output means are satisfactory for guiding offset masters into the input and output openings of one or more transporters arranged according to the invention.

It will thus be seen that the transporter according to the invention accomplishes the above stated objects in successfully transporting an offset master sheet while allowing full and uniform processing of its emulsion coating without marring or damage and while compensating for the tendency of such sheets to curl as they are processed. The inventive transporter at the same time is economical to build and convenient and economical to repair, service, and maintain. Transporters according to the invention can be quickly disassembled and reassembled, cleaned, and repaired by relatively unskilled persons using the simplest of tools and for some operations, no tools at all. Transporters according to the invention are made of con venient interchangeable parts and assemblies for further economy in repair and replacement.

Of course, the various driving means can be changed, and the number and arrangement of parts can be varied Within the spirit of the invention. Various materials can be substituted for the illustrated parts of the invention, and while the invention has been disclosed, herein by reference to the details of a preferred embodiment, it is to be understood that such disclosure is intended in an illustrative, rather than a limiting sense, and it is contemplated that various modifications of the construction and arrangement of the parts will readily occur to those skilled in the art, within the spirit of the invention and the scope of the appended claims.

We claim:

1. Means for transporting offset master'sheets through a processing solution, said transporting means comprising:

(a) a first assembly comprising drive means including upper and lower pulley shafts coupled by means of a gear train for providing a uniform driving relationship, and a plurality of continuous belts entrained over pulley means on said upper and lower pulley shafts to be driven uniformly thereby;

(b) a second assembly comprising a first plurality of rollers substantially parallel with said upper and lower pulley shafts and arranged on one side of said first assembly so that said firstplurality of rollers engage said belts at spaced positions along said belts, said first plurality of rollers being driven by roller gears engaging said gear train;

(c) a third assembly comprising a second plurality of rollers substantialy parallel with said upper and lower pulley shafts and arranged on the other side of said first assembly so that said second plurality of rollers engage said belts at spaced positions along said belts, said second plurality of rollers being driven by roller gears engaging said gear train; and

((1) each of said assemblies being separable as a unit.

2. The transporting means of claim 1 arranged for transporting said offset master sheets down one side of said belts and up the other side of said belts through successive nips formed by said rollers and belts and having means arranged beneath said lower pulley shaft for turning said sheets from said downward movement to said upward movement, said turning means comprising a backing plate arranged under said lower pulley shaft and a plurality of wires secured to said backing plate and substantially conforming to the curvature of said pulley means on said lower pulley shaft.

3. The transporting means of claim 1 wherein said rollers and roller gears in said first and second assemblies are held in position by means of springs, and are removable from their respective positions by manual displacement of said springs.

4. Means for transporting offset master sheets through a processing solution, said transporting means comprismg:

(a) a first assembly comprising drive means including upper and lower pulley shafts coupled by means of a gear train by providing a uniform driving relationship and a plurality of continuous belts entrained over pulley means on said upper and lower pulley shafts to be driven uniformly thereby;

(b) a pair of roller assemblies each comprising a plurality of substantially parallel rollers, the rollers in each of said assemblies being substantially coplanar, and springs arranged for retaining said rollers in each of said assemblies so that said rollers are removable from their respective assemblies by manual displacement of said springs;

(c) means for securing one of said pair of roller assemblies on one side of said first assembly and the other of said pair of roller assemblies on the other side of said first assembly so that said rollers engage said belts at spaced positions along said belts to form a succession of nips between said rollers and belts through which said offset master sheets can be transported down one side of said transporting means and up the other side of said transporting means; and

(d) gear means arranged so that rollers are driven by said drive means.

5. The transporting means of claim 4 having means arranged beneath said lower pulley shaft for turning said sheets from said downward movement to said upward movement, said turning means comprising a backing plate arranged under said lower pulley shaft and provided with a plurality of transversely spaced bearing ridges substantially conforming to the curvature of said pulley means on said lower pulley shaft.

6. The transporting means of claim 4 wherein said roller assemblies include supporting frames; said rollers 6 have axial projections extending beyond each end of said rollers; notched sleeves are arranged on said axial projections and adapted for engaging the edges of slots formed in said supporting frames to support said rollers; and said springs are arranged for engaging said sleeves.

7. The transporting means of claim 6 wherein said supporting frames are secured together in such a relation as to support said first assembly.

8. A device for transporting photosensitive web material through a processing solution comprising:

(a) drive means including upper and lower pulley shafts coupled by means of a gear train for providing a uniform drive relationship, said pulley shafts having pulley means thereon;

(b) belt means entrained on said pulley means to be driven uniformly by said drive means;

(0) a plurality of rollers contacting said belt means at spaced positions along said belt means so that said web material passes through successive nips formed by said rollers and said belt means;

(d) means for maintaining said rollers in place by springs and rendering said rollers removable from said device; and drive means including said gear train and roller mounted gears coupled thereto for driving said rollers.

9. A device for transporting photosensitive web material through a processing solution comprising:

(a) a first assembly including a drive means including upper and lower pulley shafts coupled by means of a gear train providing a uniform driving relationship and belt means entrained on pulley means aflixed to said upper and lower pulley shafts;

(b) a second assembly including a support frame and a first plurality of rollers having notched sleeves at terminal portions thereof adapted to engage cut out portions formed in said support frame and further including spring means for maintaining said rollers in said out out portions and rendering said rollers removable from said device and roller drive means including said gear train and roller mounted gears coupled thereto for driving said rollers;

(c) a third assembly including a support frame and a second plurality of rollers having notched sleeves at terminal portions thereof adapted to engage cut out portions formed in said support frame and further including spring means for maintaining said rollers in said out out portions and rendering said rollers removable from said device and roller drive means including said gear train and roller mounted gears coupled thereto for driving said rollers.

References Cited by the Examiner UNITED STATES PATENTS 1,229,945 6/ 1917 Greene -13 2,913,973 11/1959 Bull 95-94 3,078,024 2/1963 Sardeson 226-119 M. HENSON WOOD, JR., Primary Examiner.

J. N. ERLICH, Assistant Examiner. 

1. MEANS FOR TRANSPORTING OFFSET MASTER SHEETS THROUGH A PROCESSING SOLUTION, SAID TRANSPORTING MEANS COMPRISING: (A) A FIRST ASSEMBLY COMPRISING DRIVE MEANS INCLUDING UPPER AND LOWER PULLEY SHAFTS COUPLED BY MEANS OF A GEAR TRAIN FOR PROVIDING A UNIFORM DRIVING RELATIONSHIP, AND A PLURALITY OF CONTINUOUS BELTS ENTRAINED OVER PULLEY MEANS ON SAID UPPER AND LOWER PULLEY SHAFTS TO BE DRIVEN UNIFORMLY THEREBY; (B) A SECOND ASSEMBLY COMPRISING A FIRST PLURALITY OF ROLLERS SUBSTANTIALLY PARALLEL WITH SAID UPPER AND LOWER PULLEY SHAFTS AND ARRANGED ON ONE SIDE OF SAID FIRST ASSEMBLY SO THAT SAID FIRST PLURALITY OF ROLLERS ENGAGE SAID BELTS AT SPACED POSITIONS ALONG SAID BELTS, SAID FIRST PLURALITY OF ROLLERS BEING DRIVEN BY ROLLER GEARS ENGAGING SAID GEAR TRAIN; (C) A THIRD ASSEMBLY COMPRISING A SECOND PLURALITY OF ROLLERS SUBSTANTIALLY PARALLEL WITH SAID UPPER AND LOWER PULLEY SHAFTS AND ARRANGED ON THE OTHER SIDE OF SAID FIRST ASSEMBLY SO THAT SAID SECOND PLURALITY OF ROLLERS ENGAGE SAID BELTS AT SPACED POSITIONS ALONG SAID BELTS, SAID SECOND PLURALITY OF ROLLERS BEING DRIVEN BY ROLLER GEARS ENGAGING SAID GEAR TRAIN; AND (D) EACH OF SAID ASSEMBLIES BEING SEPARABLE AS A UNIT. 